Put the summary of the bug you're having here
What I expected to happen was...:
The netherite ingots won't duplicate itself
What actually happened was...:
The netherite ingots duplicated itself when I quit the game
Steps to Reproduce:
Video description: https://youtu.be/hA6nMa7NnYw
Text description:
1. Craft a netherite ingot
2. Place down a hopper
3. Quit the world
4. Open the world again
5. Right click the hopper
6. Without quitting the hopper menu, press Ctrl+Shift+Esc on the keyboard
7. This will open the task manager. Click on OpenJDK and then click on End Task
8. This will close Minecraft. Open Minecraft again
9. A netherite ingot should appear both inside the hopper and in the inventory.
10. Put the netherite ingot in the inventory to the hopper, and repeat steps 6-10. The amount of netherite ingots should grow exponentially.
Related issues
Comments

Thank you for your report!
We're tracking this issue in MC-63, so this ticket is being resolved and linked as a duplicate.
If you would like to add a vote and any extra information to the main ticket it would be appreciated.
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Duplicate of MC-63.